> Of course since no one knows how long intelligent civilizations last, (given our current trajectory, some might guess not very long)
These people must have a very short sighted view of history? Our current trajectory for almost everything that matters is positive. Longer life spans, fewer wars, better medicine and technology, average base-level knowledge, etc. Barring some global unavoidable catastrophe, there is no reason to think we are going anywhere very soon.
Cosmic timescales are different. Do you think humans will be around for the next say 100,000,000 years? I think we'd be lucky to survive another 10,000.
We've only had organized societies for somewhere around 20,000.
There could have been say, intelligent life on Venus, then they triggered a runaway greenhouse effect, everything died, the oceans boiled, and then 700,000,000 years pass before we started talking pictures of the dead planet with all signs of previous life completely erased.
If we burned this planet down and waited 700,000,000 years, would remnants of our civilisation remain? On the one hand, we have structures that are massive blocks of concrete and metal that I find hard to imagine fading away. We've got stuff in space and on the moon. On the other hand, there's weathering and erosion which would be amplified by chaotic weather patterns. And 700 million years is a long time.
I'm leaning towards us leaving some evidence behind, but it's such an inconceivable amount of time that I'm not really sure.
In the case of Venus there's likely little left due to extreme volcanic activity[0]. Even if we didn't create a hellscape like Venus on Earth, over 700,000,000 years geological processes would grind those structures to dust. Repeated glaciation every 41,000 years or so would act the fastest but over hundreds of millions of years the surface would be significantly altered by tectonic movement. Add to that all the insults of rain, oceans, rivers, wind, volcanism, and biology. Practically nothing would be left except for maybe the fossilized remains of some junk thrown into rivers that managed to sink into the mud and then ride the tectonic waves up onto some high escarpment. Even the orbits of satellites decay. The few artifacts we left on the Moon would stand the best chance. This is why the only hope we have is to spread out into the solar system and beyond. If we stay in our tiny ecological niche on this island we're doomed to extinction and erasure.
Near-Earth satellites, yes; the thinnest wisps of the edge of the atmosphere slow them down. Further out, however, in geostationary orbit, satellites are not subject to such forces. They may be disrupted long-term by the gravitational influence of other distant bodies, but I think I'd worry more about the potential impact from micrometeorites.
> If we burned this planet down and waited 700,000,000 years, would remnants of our civilisation remain?
I've seen this discussed a bunch over the years, and the informed answer to me seems to be that various isotopes and such would remain in trace amounts as clear evidence of technology.
I wonder how much our chances of surviving as a species change if we drastically increase the average lifespan of an individual. I think this might also be a solution for interstellar travel as well. If we're going to conquer the depths of space we need to take control of our biology first.
You're only looking at the positive side of things and ignoring well known issues that will lead to global catastrophe. Consider climate change, loss of biological diversity, soil erosion, mineral resource exhaustion, pandemics, etc. The possible solutions to these issues require global cooperation which we haven't seen yet. Market solutions don't seem to be panning out well.
Market solutions work when applied to the correct areas, same thing with global cooperation. Too much interdependence in the wrong areas can be a hinderance. There is no panacea, we have to be smarter than that.
> Barring some global unavoidable catastrophe, there is no reason to think we are going anywhere very soon.
If only we didn't live during a huge ecological disaster that is threatening to destroy the livelihoods of hundreds of millions of people directly, with unforeseeable consequences for the rest of the world; which the major powers of the world are unwilling to act in any significant way to curtail; and which seems to require a re-structuring of the entire world's economy to actually solve...
Looking at the world right now, we know one thing for sure: none of the trends we see today will be relevant in 100 years. One way or another, the world will go through massive changes whose scope can't be predicted.
One possibility is global warming will continue unabated until we have hundreds of millions of people migrating from rapidly submerging areas (Bangladesh being one of the largest concentrations of population in the world living a few meters above sea levels), most likely followed by some kind of global war to prevent or redirect the massive migrations.
Another is that the global economy will be completely re-created to stop the production of greenhouse gases dead in its tracks, almost certainly in a non-capitalist system, since capitalism simply can't deal with externalities. The required political and economic shifts are hard to imagine, and the resulting world is equally hard to predict.
And of course, we are still always a few madmen away from nuclear war, with many of the world's most tense regions having nuclear weapons aimed at their enemies. Could global warming start a resource war between India and Pakistan that would lead to them using their arsenals? Could Israel decide to use its illegal nuclear weapons to attack Iran in a "defensive first strike"? Could the US decide that its interests are important enough that, as its soft power wanes, it could launch a bomb at some country to remind everyone of its hard power? Could the Europeans spark a new war, either among themselves or against some common threat, and feel the need to use their nuclear arsenal? Could the Chinese? As long as nuclear weapons exist, they are an ever growing threat.
Remember that just in the last few years, the long standing US-Russian non-proliferation treaty was unilaterally ended by the US, signalling a vast increase in the risk of nuclear weapons actually seeing use again.
First of all, there's no need for 7 billion people to exist to fulfill being a civilization. Surely our civilization could exist of just 1 million people if it comes to that.
Secondly, the climate change "catastrophe" isn't what we need to be worried about. Rather one of those events that has occurred before on earth, wiping out almost all existing life. But considering some non-intelligent life forms, or at least life forms without our superior intelligence, survived those events I'd bet that we would survive them too. Considering we can detect them, and (somewhat) protect against them.
Nuclear War is unlikely to happen since any instigator know it would come at tremendous cost. Also, the more countries that have nukes the better, since it levels the playground. Even if nuklear war happens, it wont wipe out all people, all communities.
If in a group of a million people you had enough people interested in and capable of doing the science necessary for making progress interstellar communication or travel, we would have many many many times more people working in those fields today.
A civilization with only a million people in it would have priorities vastly different than our own.
The human species doesn't need to be wiped out for civilization to end,at least at the level of being interested in interstellar communication. It's true tho that civilization may spring up again after some time, so perhaps that should be factored into the equation.
And nuclear war had been only narrowly avoided on around 13 documented occasions in the last 70 years [0]. Some of these events were avoided by happenstance, not any kind of systematic protection. This kind of luck will not continue forever. And if it does break out, right now we don't really understand what may happen to the planet if the US or Russia unleash their full nuclear arsenal, rather than just bombing one or two cities.
> right now we don't really understand what may happen to the planet if the US or Russia unleash their full nuclear arsenal
Nothing will happen. Planetary nuclear arsenal yield is dwarfed by a single large vulcanic eruption, and those happen regularly. In fact, modern nuclear arsenal is barely enough to destroy military targets and major cities of both parties. Direct casualties will be in millions, but probably in single digits of them.
In other words, it will be a major humanitarian catastrophe, but nothing humanity (or even a major world power like US) can't survive. Probably the biggest change would be due to large areas rendered uninhabitable for decades, but then again, plenty will be left and "uninhabitability" is a matter of life quality standards. People live in Hiroshima and Chernobyl just fine.
You're free to believe what you want, but the peer reviewed studies that have been conducted with current climactic models predict significant global cooling that would lead to at least global famine. The crux is not the power of the explosion, but the amount of soot generated by detonating high - yield weapons in huge cities.
And people do not live in Chernobyl at all. However, it's not really relevant to a discussion of nuclear weapons, as nuclear plant meltdowns are a completely different problem. For sure if the Chernobyl core had melted down and exploded nothing would be living in Ukraine at all, and possibly a much larger area. Hopefully though, that is one area though where technological progress has actually significantly reduced the chance that it would ever happen, in a systematic manner.
Not matter the opinion, "nuclear winter" concept is a belief, you are totally right here. It has never been a scientific question in the first place, the idea was largely accepted for political reasons. Wikipedia [1] has a short overview of the discussion on the topic, but in reality there is no debate on that for a long time: one can't really argue in favor of milder consequences because he'd be labeled as a militarist and all. And I agree that this is one of the few discussions that we probably shouldn't have.
But in general: all the articles greatly exaggerate the volume of nuclear arsenal (tenfold), the number of actual nuclear detonations, the territory of fire and ash yield of the fires. And even then, the planet has tolerated all those at larger scale in volcanic eruptions and forest fires.
Napkin math: US/Russia arsenal is about 1500 warheads on 500-1000 carriers each, which is about 500MT combined. Out of those optimistically maybe a half will detonate on each side (they will be destroyed in preventive strikes/intercepted/etc.), which leaves you with about 125MT total yield - about the yield of a couple of Tsar Bombs that was detonated in 1961 without any consequences whatsoever. The majority of the strikes will be on military targets in the middle of nowhere, where there won't be any fire at all. The rest will fall on modern concrete cities that don't have much fuel either.
> And people do not live in Chernobyl at all
They do, there are about 3000 people working there at any given time and even more living there illegally. Also, animals have no problems living there whatsoever and in fact the ecosystem is in a better shape due to low human activity. Also, you are aware, that Chernobyl power plant itself was operational until year 2000, right?
> nuclear plant meltdowns are a completely different problem
I absolutely is, and in terms of ecological consequence Chernobyl is far more severe than thermonuclear warhead detonation. The core HAS melted down and exploded, pieces of graphite rods were found as far as hundreds of meters away from the building.
I'm not saying nuclear war is nothing to think about - this would be a major catastrophe. But it's very unlikely to end the civilization.
The Chernobyl facts you bring up are very interesting. I had no idea that the plant kept operating for so long. I knew that there were people who stayed behind, and that there are workers around the exclusion area, though I admit that I would have imagined significantly lower numbers.
> Also, the more countries that have nukes the better, since it levels the playground.
That's the American "best thing against a bad guy with a gun is a good guy with a gun" attitude. Empirically this does not hold true. With the density of lethal weapons in the U.S. and the statistically lower safety from gun violence compared to other developed countries, it's safe to assume that the world would be a safer place with a reduced number of countries having nukes (or ideally none of them) rather than an increased number.
I'm not sure that it's safe to assume that the dynamics of international relations among nuclear and nonnuclear states can be so tidily extrapolated from the dynamics of society and interpersonal relations among gun-owning and non-gun-owning humans acting in their individual capacities.
Maybe not. But it's at least an attempt to a somewhat informed hypothesis, which a simple statement like "since it levels the playground" definitely is not.
These people must have a very short sighted view of history? Our current trajectory for almost everything that matters is positive. Longer life spans, fewer wars, better medicine and technology, average base-level knowledge, etc. Barring some global unavoidable catastrophe, there is no reason to think we are going anywhere very soon.